Hierarchical Control of Droop-Controlled AC and DC Microgrids—A General Approach Toward Standardization

This paper proposes a hierarchical control structure for both AC and DC droop-controlled microgrids. The control hierarchy consists of three levels: primary control based on droop method, secondary control to restore deviations produced by the primary control, and tertiary control to regulate the power flow between the microgrid and the external grid. The proposed control architecture is compatible with both AC and DC microgrids, providing a general approach toward standardization of microgrid control.